Recently, steps have been taken to introduce synthetic hydrocarbons to aviation fuels as biocomponents.
This action is an innovative change in the approach to aviation fuels. This new approach to the assessment
of fuel properties requires a revision of the existing criteria for their quality assessment, including those
relating to tribological properties. In the requirements for Jet fuel, only the BOCLE test simulating continuous
circular motion was used to assess lubricity. Research on the use of fuels containing components with highly
differentiated chemical compositions indicate that the BOCLE test may be an insufficient criterion for
assessing the lubricity of fuels for aircraft turbine engines. An additional HFRR test modelling the processes
accompanying the reciprocating friction that occurs in some lubricated elements of the fuel system has been
proposed. This article presents the results of BOCLE and HFRR tests on a range of Jet A1 fuel mixtures
and various synthetic paraffin hydrocarbons. A preliminary analysis of the observed effect of synthetic
hydrocarbons on the results of both tests is presented.